Can dolphins or whales live in fresh water?
They don’t need to breathe in water so assuming they have enough prey I don’t see why the water’s saltinity affects them.
But then why don’t we have dolphins playing in the Mississippi river?
Can dolphins or whales live in fresh water?
They don’t need to breathe in water so assuming they have enough prey I don’t see why the water’s saltinity affects them.
But then why don’t we have dolphins playing in the Mississippi river?
There are types of freshwater river dolphins in the Yangtze (well, one of these species probably is extinct there as of recently but still) and the Amazon, for example. Sea dolphins can survive in freshwater for awhile but their skin isn’t adapted to it, and it will get damaged eventually. That and the difference in buoyancy in sea water vs freshwater leads to the sea dolphins eventually getting exhausted in freshwater.
Not in the Yangtze anymore :(
There is still a bit of the Finless Porpoise left there, but not dolphins specifically no.
They probably cut the fins off to make soup.
I would think marine mammals are also adapted to the level of salt in their diet. So not just food abundance but its salt content could be important.
That said, I know orcas like to drink freshwater if they can get it. So salinity may not be required. Their adaptations are likely built around eliminating salt, and therefore may not be stressed at all by low salt food.
Yeah from my brief reading it seems they can adapt to food salinity by altering their urine concentrations so I don’t think that’s a huge factor, at least it’s not something that comes into play before the other factors begin to harm them. But if you could fix their skin and buoyancy, diet may start to matter. But their prey is also a different salinity than the water it lives in a lot of the time, and sometimes they eat land animals like birds and such ofc.